WotC stopping production of D&D won't change anything - someone will come along and buy the D&D name and IP;
I don't think that would happen. Hasbro as far as I know has never sold a IP once they owned it. Instead the mothball them and then in 10, 20 years later they bring them back and see if they stick. If 5E fails I wouldn't be remotely surprised if that doesn't happen.